// Copyright 2009 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#if V8_TARGET_ARCH_ARM

#include "src/arm/constants-arm.h"

namespace v8 {
namespace internal {

    Float64 Instruction::DoubleImmedVmov() const
    {
        // Reconstruct a double from the immediate encoded in the vmov instruction.
        //
        //   instruction: [xxxxxxxx,xxxxabcd,xxxxxxxx,xxxxefgh]
        //   double: [aBbbbbbb,bbcdefgh,00000000,00000000,
        //            00000000,00000000,00000000,00000000]
        //
        // where B = ~b. Only the high 16 bits are affected.
        uint64_t high16;
        high16 = (Bits(17, 16) << 4) | Bits(3, 0); // xxxxxxxx,xxcdefgh.
        high16 |= (0xFF * Bit(18)) << 6; // xxbbbbbb,bbxxxxxx.
        high16 |= (Bit(18) ^ 1) << 14; // xBxxxxxx,xxxxxxxx.
        high16 |= Bit(19) << 15; // axxxxxxx,xxxxxxxx.

        uint64_t imm = high16 << 48;
        return Float64::FromBits(imm);
    }

    // These register names are defined in a way to match the native disassembler
    // formatting. See for example the command "objdump -d <binary file>".
    const char* Registers::names_[kNumRegisters] = {
        "r0",
        "r1",
        "r2",
        "r3",
        "r4",
        "r5",
        "r6",
        "r7",
        "r8",
        "r9",
        "r10",
        "fp",
        "ip",
        "sp",
        "lr",
        "pc",
    };

    // List of alias names which can be used when referring to ARM registers.
    const Registers::RegisterAlias Registers::aliases_[] = {
        { 10, "sl" }, { 11, "r11" }, { 12, "r12" }, { 13, "r13" },
        { 14, "r14" }, { 15, "r15" }, { kNoRegister, nullptr }
    };

    // Support for VFP registers s0 to s31 (d0 to d15) and d16-d31.
    // Note that "sN:sM" is the same as "dN/2" up to d15.
    // These register names are defined in a way to match the native disassembler
    // formatting. See for example the command "objdump -d <binary file>".
    const char* VFPRegisters::names_[kNumVFPRegisters] = {
        "s0", "s1", "s2", "s3", "s4", "s5", "s6", "s7",
        "s8", "s9", "s10", "s11", "s12", "s13", "s14", "s15",
        "s16", "s17", "s18", "s19", "s20", "s21", "s22", "s23",
        "s24", "s25", "s26", "s27", "s28", "s29", "s30", "s31",
        "d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7",
        "d8", "d9", "d10", "d11", "d12", "d13", "d14", "d15",
        "d16", "d17", "d18", "d19", "d20", "d21", "d22", "d23",
        "d24", "d25", "d26", "d27", "d28", "d29", "d30", "d31"
    };

    const char* VFPRegisters::Name(int reg, bool is_double)
    {
        DCHECK((0 <= reg) && (reg < kNumVFPRegisters));
        return names_[reg + (is_double ? kNumVFPSingleRegisters : 0)];
    }

    int VFPRegisters::Number(const char* name, bool* is_double)
    {
        for (int i = 0; i < kNumVFPRegisters; i++) {
            if (strcmp(names_[i], name) == 0) {
                if (i < kNumVFPSingleRegisters) {
                    *is_double = false;
                    return i;
                } else {
                    *is_double = true;
                    return i - kNumVFPSingleRegisters;
                }
            }
        }

        // No register with the requested name found.
        return kNoRegister;
    }

    int Registers::Number(const char* name)
    {
        // Look through the canonical names.
        for (int i = 0; i < kNumRegisters; i++) {
            if (strcmp(names_[i], name) == 0) {
                return i;
            }
        }

        // Look through the alias names.
        int i = 0;
        while (aliases_[i].reg != kNoRegister) {
            if (strcmp(aliases_[i].name, name) == 0) {
                return aliases_[i].reg;
            }
            i++;
        }

        // No register with the requested name found.
        return kNoRegister;
    }

} // namespace internal
} // namespace v8

#endif // V8_TARGET_ARCH_ARM
